English
Related papers

Related papers: Is there Correlation between Fine Structure and Da…

200 papers

We present the detection of excited fine-structure energy levels of singly-ionized silicon and neutral carbon associated with the proximate damped Lyman-$\alpha$ system at $z_{\rm abs}=2.811$ towards \qso. This absorber has an apparent…

Astrophysics of Galaxies · Physics 2020-07-29 S. A. Balashev , C. Ledoux , P. Noterdaeme , R. Srianand , P. Petitjean , N. Gupta

The dipole anisotropy seen in the {cosmic microwave background radiation} is interpreted as due to our peculiar motion. The Cosmological Principle implies that this cosmic dipole signal should also be present, with the same direction, in…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-24 Carlos A. P. Bengaly , Thilo M. Siewert , Dominik J. Schwarz , Roy Maartens

This letter explores the derivation of dark energy from a locally conformal projection of hyperconical universes. It focuses on the analysis of theoretical compatibility between the intrinsic view of the standard cosmology and an adequate…

General Physics · Physics 2018-08-30 Robert Monjo

Anisotropies in the distance-redshift relation of cosmological sources are expected due to large-scale inhomogeneities in the local Universe. When the observed sources are tracing a large-scale matter flow in a general spacetime geometry,…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-05 Julian Adamek , Chris Clarkson , Ruth Durrer , Asta Heinesen , Martin Kunz , Hayley J. Macpherson

We report coincident damped Lyman alpha (DLA) and sub-DLA absorption at z = 2.66 and z = 2.94 towards the z ~ 3 13.8 arcsecond separation binary quasar SDSS 1116+4118 AB. At the redshifts of the absorbers, this angular separation…

Astrophysics · Physics 2009-06-23 Sara L. Ellison , Joseph F. Hennawi , Crystal L. Martin , Jesper Sommer-Larsen

The cosmological principle states that our Universe is statistically homogeneous and isotropic at large scales. However, due to the relative motion of the Solar System, an additional kinematic dipole can be detected in the distribution of…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-31 Yu-Tian Xu , Ji-Ping Dai , Dong Zhao , Jun-Qing Xia

If gamma-ray bursts originate at cosmological distances then their angular distribution should exhibit a dipole in the direction of the solar motion relative to the cosmic microwave background. This is due to the combined effects of…

Astrophysics · Physics 2009-10-22 Eyal Maoz

In this work a satisfactory, simple theoretical prediction of the data corresponding to observationally (by fine tuning condition) estimated value of the cosmological constant is given. It is supposed (in conceptually analogy with…

Astrophysics · Physics 2007-12-27 Vladan Pankovic , Simo Ciganovic , Jovan Ivanovic , Rade Glavatovic , Petar Grujic

The Cosmological Principle is part of the foundation that underpins the standard model of the Universe. In the era of precision cosmology, when stress tests of the standard model are uncovering various tensions and possible anomalies, it is…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-16 Caroline Guandalin , Jade Piat , Chris Clarkson , Roy Maartens

The optical spectra of objects classified as QSOs in the SDSS DR6 are analyzed with the aim of determining the value of the fine structure constant in the past and then check for possible changes in the constant over cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 C. M. Gutierrez , M. Lopez-Corredoira

The cosmological principle states that the Universe is statistically homogeneous and isotropic at large distance scales. There currently exist many observations which indicate a departure from this principle. It has been shown that many of…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-31 Shamik Ghosh , Pankaj Jain , Rahul Kothari , Mohit Panwar , Gurmeet Singh , Prabhakar Tiwari

The partial spatial separation of cold dark matter (DM) and gas is a ubiquitous feature in the formation of cosmic large-scale structure. This separation, termed dissociation, is prominent in galaxy clusters that formed through collisions…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-07 William McDonald , Danail Obreschkow , Lilian Garratt-Smithson

In this paper we use $\alpha'^2$-corrections to the $D_{3}$-brane action to obtain a non-zero and positive cosmological constant in the induced cosmology living on the dark bubble. Its measured value, together with the value of the fine…

High Energy Physics - Theory · Physics 2023-11-28 Ulf Danielsson , Daniel Panizo

A cosmological model with anisotropic dark energy is analyzed. The amount of deviation from isotropy of the equation of state of dark energy, the skewness \delta, generates an anisotropization of the large-scale geometry of the Universe,…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-28 L. Campanelli , P. Cea , G. L. Fogli , L. Tedesco

Spatial and temporal variations in the electron-to-proton mass ratio, mu, and in the fine-structure constant, alpha, are predicted in non-Standard models aimed to explain the nature of dark energy. Among them the so-called chameleon-like…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-20 S. A. Levshakov , I. I. Agafonova , P. Molaro , D. Reimers

Recent analyses of large-scale structure and redshift surveys have reported significant dipolar anisotropies in the local Universe that are not straightforwardly attributable to a global kinematic boost. When interpreted within standard…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-05 Erick Pastén

We probe the anisotropy of the large-scale structure (LSS) with the WISE-2MASS catalogue. This analysis is performed by a directional comparison of the galaxy number counts through the entire celestial sphere once systematic effects, such…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-23 C. A. P. Bengaly , A. Bernui , J. S. Alcaniz , H. S. Xavier , C. P. Novaes

We theoretically analyze the dipole anisotropy observed in the quasar distribution from the CatWISE2020 catalog. The catalog data shows a peak around $z\approx 1$, suggesting the presence of a large-scale dipole component. We explore the…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-16 Gopal Kashyap , Naveen K. Singh , Pankaj Jain

A model of dark matter and dark energy based on the concept of gravitational polarization is investigated. We propose an action in standard general relativity for describing, at some effective or phenomenological level, the dynamics of a…

Astrophysics · Physics 2008-12-18 Luc Blanchet , Alexandre Le Tiec

Recent work by Webb {\it et al.} has provided indications of spatial variations of the fine-structure constant, $\alpha$, at a level of a few parts per million. Using a dataset of 293 archival measurements, they further show that a dipole…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-16 A. M. M. Pinho , C. J. A. P. Martins
‹ Prev 1 3 4 5 6 7 10 Next ›